Stator and rotor cores of electrodynamic machines, such as generators, in most cases are formed as laminated cores which comprise lamination stacks of individual lamination segments, which stacks are held together with bolts. Slots which extend in the axial direction for accommodating the corresponding windings are arranged in the laminated cores on the inner or outer periphery. The rotor of such a machine is described for example in EP-A2-0 736 953.
In the case of high-performance machines, by inserting duct spacers between adjacent stack sections of the laminated core, radial cooling ducts are formed, through which a suitable cooling medium, for example cooling air, flows in order to dissipate the heat which ensues in the winding or in the laminated core during operation.
Conventional duct spacers for stators, as are known for example from publications EP-A2-0 893 871 or U.S. Pat. No. 4,362,960 or U.S. Pat. No. 6,583,526, are normally produced as double-T or rectangular profiles consisting of steel, non-magnetic steel or aluminum and are fastened on the lamination segments by means of spot-welding or adhesive bonding.
For fast-rotating laminated cores of rotors, adhesive bonding or spot-welding of the duct spacers no longer suffices on account of the high centrifugal forces.